The present invention relates to apparatus for transporting carton blanks in a packaging machine from a pitched carton pick mechanism to an unpitched carton folding mechanism.
In known packaging machines which are pitched, for example machines for producing multipacks of bottles or cans, carton blanks are held in a magazine and are picked off one by one by a carton feeder before being transported in a pitched manner to an area where they are folded around the articles to be packed. In a packaging machine which is not pitched, the carton blanks have to be transported to the folding area in back to back fashion, aligned with the unpitched articles supplied by the infeed mechanism of the packaging machine.
According to the present invention there is provided transport apparatus for transporting carton blanks from a pitched carton pick mechanism to an unpitched carton folding mechanism, said transport apparatus comprising: a pair of nip rollers for rotation at a first speed which rollers receive the carton blanks at pitched intervals, at least one pair of opposed endless belts which in use move at an identical second speed, the belts defining therebetween a gap, the blank being received in the gap and conveyed by the belts, the gap at the upstream end of the belts nearest the nip rollers being widened such that the nip rollers accelerate the blanks into the widened gap, the distance between the nip rollers and the non-widened section being substantially equal to the carton length such that downstream of the widened section the successive blanks are disposed in end to end relationship.
Preferably two pairs of endless belts are provided at laterally spaced locations for receiving lateral extremities of the cartons. In preferred arrangements the gaps between the pairs of belts widen slightly at their downstream ends to facilitate removal of the extremities of the cartons.
In some arrangements the length of the widened upstream section between the nip rollers and the non-widened section of the endless belts is variable to enable the apparatus to be used with cartons of different lengths. Conveniently the upstream end of one belt of each pair is guided by two spaced guide rolls at its upstream end, the axes of the rolls being located on a line parallel to the path of travel through the non-widened section, the most upstream first guide roll being of smaller diameter than the second guide roll which constitutes the junction of the widened upstream section, the smaller diameter first guide roll effecting said gap widening.
A preferred feature is that the axis of the second guide roll is movable along said parallel line to effect the variable length of the widened upstream section. Normally the lower belt of each pair is provided with said first and second guide rolls.
Typically the upstream widened section and the non-widened section of the endless belts are angled downwardly so as, in use, to approach from above a stream of product moving unpitched along a substantially horizontal product path. Also the downstream widened section of the endless belts is substantially parallel to and above part of the horizontal product patch so as, in use, to place the successive carton blanks on to successive groups of products as side folding arms engage the blank and pull the lateral extremities of the blank from between the pairs of endless belts.
An embodiment of the present invention will now be described in more detail.